Answer:
21.5 N
Explanation:
As the block is pulled to a distance of 0.25 m to the left of its equilibrium position, the left spring is compressed by x = 0.25 m and exerting an elastic force to the right, the right spring is stretched by x =0.25 m and also exerting an elastic force to the right. Knowing their spring constant, we can calculate the total net force at that instant
[tex]F = F_{left} + F_{right}[/tex]
[tex]F = k_{left}x + k_{right}x[/tex]
[tex]F = x(k_{left} + k_{right}) = 0.25(36 + 50) = 0.25*86 = 21.5 N[/tex]
